The “war on drugs” has failed to curtail the $350 billion annual trade in illegal narcotics over the last 20 years as the price of drugs has declined while potency has increased, according to study results released this week.

The prices of heroin and cocaine, for example, have decreased by 81 percent and 80 percent respectively in the United States between 1990 and 2007, despite increasing law enforcement efforts to disrupt drug supply, research published Tuesday in the British Medical Journal Open showed.

The study said marijuana seizures in the U.S. increased 465 percent between 1990 and 2009. During the same period, though, the average inflation-adjusted prices of pot decreased by 86 percent, while the drug’s potency increased by 161 percent.

“Organized crime has really overwhelmed law enforcement's best intentions to reduce the availability of drugs,” Dr. Evan Wood, a co-author of the study from the University of British Colombia, told Al Jazeera America. “It (the study) really calls for a total rethink on how society deals with drug use and drug addiction.”

The U.S.-led war on drugs has increasingly come under fire in the United States and abroad, with critics highlighting the program’s negative impact on public health. And yesterday’s study shows that illegal drug use remains a major menace to community health and safety. The study’s authors suggested that governments assess the effectiveness of their drug policies by using indicators such as overdose rates and the rate of blood-borne disease transmission, particularly HIV infection.

“We should look to implement policies that place community health and safety at the forefront of our efforts, and consider drug use as a public health issue rather than a criminal justice issue,” Wood said.

The Organization of American States (OAS), in a report on drug problems in the Americas released last May, also emphasized drug abuse as a public health issue. The report calls for a public health approach to address the global drug epidemic. “The decriminalization of drug use needs to be considered as a core element in any public health strategy,” the study concluded.

Public health is a central component of the recreational marijuana measure approved byWashington State voters last November. The law will place a 25 percent tax on all marijuana transactions, generating an estimated $1.9 billion within five years, according to the Washington State Office of Financial Management. Fifty percent of that revenue would go to the state’s basic health plan, while substance-abuse prevention programs will receive 15 percent the revenue.

The drug war, the BMJ Open study shows, is also rife with unintended consequences. Incarceration rates, especially in the U.S., have skyrocketed in the last two decades. With more than 2.2 million Americans in prison, the U.S. has the highest incarceration rate in the world – 1 in every 99 adults. In 2011, there were more than 750,000 people under arrest in U.S. prisons for marijuana violations, with 87 percent of those inmates under arrest for possession only.

The study’s findings brought renewed calls to reexamine the effectiveness of global strategies that emphasize drug supply reduction at the expense of evidence-based prevention and treatment.

“In response to a study like this, policymakers often say, ‘drugs are harmful so they must be kept illegal,’” said Fernando Henrique Cardoso, the former president of Brazil and chair of the Global Commission on Drugs. “What they fail to consider is, as this and other research suggests, that drugs are more harmful – to society, individuals and the taxpayer – precisely because they are illegal.”